AUGUSTA, Maine — Mainers will decide whether to legalize recreational use of marijuana when they vote in November after the secretary of state’s decision to invalidate petition signatures was tossed out by a court.

If approved, the ballot question would allow Mainers to possess 2.5 ounces of marijuana and give the state regulatory power over cultivation and retail stores with a 10 percent sales tax on marijuana products.

A nationalized campaign for the law — led by the Marijuana Policy Project — finds what’s likely to be good audience in Maine, which has a long history of backing increased access to marijuana and is one of 24 states to have legalized medical marijuana.

An opposition coalition is beginning to take shape in Maine, but the state’s laid-back approach to marijuana use and national momentum toward legalization could blunt their efforts.

The law would give significant latitude to state lawmakers and regulators, so it’s unclear what the market will look like and how much revenue the state will reap.

Maine’s marijuana laws have long been more liberal than the rest of the country, and legalization proponents have national momentum and could have an edge on an in-the-works opposition coalition.

For more than a generation, Maine has pioneered in marijuana law, starting in 1976, when the Legislature decriminalized possession of small amounts, just after Oregon and Alaska. Mainers backed medical marijuana in 1999, voting to allow prescribing and limited possession.

But the latter law was somewhat toothless, because there was no way to acquire legal marijuana. In 2009, 58 percent of voters approved a new law making Maine the fifth state to allow state-licensed dispensaries, also creating a list of conditions qualifying a patient for medical marijuana.

Washington, Colorado, Oregon, Alaska and the District of Columbia have all legalized recreational marijuana use since 2012, and a handful of states are poised to consider legalization in November, with a similar question qualifying for Nevada’s ballot and others possible in Massachusetts, Florida and California.

The Marijuana Policy Project was a main driver of the Colorado and Alaska campaigns, and it has given $400,000 to the Maine campaign since 2015, according to Maine Ethics Commission records.

Nationally, that type of fundraising has put legalization opponents in a bind, and they’ve admitted it: When Oregon, Alaska and the District of Columbia legalized marijuana in 2014, Smart Approaches to Marijuana, an anti-legalization group, blamed it on a 20-to-1 spending disparity.

Scott Gagnon, a certified prevention specialist from Gray, is running that group’s outreach efforts in Maine. But even though prominent politicians, including Gov. Paul LePage and Attorney General Janet Mills, have spoken against legalization, no group has formed to formally oppose it in 2016.

Gagnon said that will change, with a coalition of health, public safety and faith-based groups discussing an effort against the question that could be announced by the end of spring, with volunteers “very committed” to defeating it amid health and safety concerns.

“Where we may lack in resources, we’ll definitely match them or exceed them in passion and drive to see this through,” Gagnon said.

Even if the referendum passes, we don’t know exactly what Maine’s recreational marijuana market will look like.

In many ways, Maine’s legalization is a sweeping bill: Not only does it regulate and tax marijuana and legalize possession amounts, it allows “marijuana social clubs,” where products can be consumed and establishes employment, education, housing and parental rights for those who use marijuana, though schools and landlords can prohibit marijuana.

But it gives a lot of authority to the state, cities and towns, which will shape the way the market will look if legalization passes. At the state level, that means the administration of LePage, who has called marijuana a “gateway” to more addictive drugs, would oversee legalization.

The Maine Department of Agriculture, Conservation and Forestry would regulate the industry, hiring 18 new employees, according to an estimate from the Legislature’s fiscal office. It would issue licenses for retail stores, social clubs and cultivation, manufacturing and testing facilities and retail stores.

Statewide, retail cultivation would be limited to 800,000 square feet, but the department could authorize more, with 40 percent of licenses going to grows of 3,000 square feet or smaller. The state can’t cap the number of retail stores, but municipalities can regulate the number and location of stores, require local licensing or prohibit them altogether.

And revenue generated under the law, which flows to the state’s General Fund, will be a multimillion-dollar question.

In Colorado, marijuana was nearly a $1 billion industry in 2015, with the state seeing $135 million in taxes. That state’s population is about four times bigger than Maine’s, so on that very rough scale, tax revenue here would nearly hit $34 million.

There has been no cost-and-benefit analysis in Maine: The Legislature’s fiscal office has gotten closest, estimating revenues of $8.8 million in the first year, but without accounting for what it said would be “significant” savings in the criminal justice system.

David Boyer, the legalization effort’s campaign manager, called tax revenue just “icing on the cake” of legalization, saying it’ll bring hundreds of jobs to the state. But he called the revenue “conservative.”

“Either way, these are millions of dollars in tax revenue on the table right now for Mainers that are otherwise being flushed down the drain,” he said.

Michael Shepherd

Michael Shepherd joined the Bangor Daily News in 2015 after three years as a reporter at the Kennebec Journal. A Hallowell native who now lives in Augusta, he graduated from the University of Maine in...